The title sounds generic. The setup seems terminally familiar: A Thanksgiving dinner with mom and dad, two daughters, live-in boyfriend and grandmother. Put them all together, and you just know that tempers will flare, resentments will surface, secrets will be spilled, feelings will be hurt and nerves will be rubbed raw.

You not only recognize this family drama, you’ve probably lived it.

Still, at the end of 90 minutes of the Tony-winning "The Humans," at the Civic Center through Sunday, you won’t quite know what has hit you. The gut-punch power and bitter humor come from playwright Stephen Karam’s attention to the specifics. He probes beneath the generalities and stereotypes for the complexities — the very individual flaws. He knows that you can only achieve the universal through the particular. In Tolstoy’s famous observation, “Each unhappy family is unhappy in its own way.”

Not that this family would consider itself unhappy. In this tragicomic ensemble piece, everyone is flawed — that is, human. Everyone is integral to the dynamic that both lifts the family up and grinds it down. Everyone more or less loves everyone else. Everybody thinks everybody else is a little nuts. And each of them is probably right.

Richard Thomas(Photo: Special to the Register)

The play opens with a man standing alone, motionless, a shopping bag in each hand, amid an ominous rumble as a sonic undercurrent. He is the patriarch, Erik Blake, played with convincing stoicism by Richard Thomas (once John-Boy in The Waltons). He appears to have the weight of Willy Loman’s world on his shoulders. When the rest of his boisterous family clamors through the door of this recently rented duplex, chaos erupts and the audience is left in the middle of an uproar, trying to discern from snatches of dialogue just who these people are, what their relation is to each other and what are their stories.

A scene from "The Humans" at the Seattle Repertory Theatre in Seattle on Nov. 28, 2017.(Photo: Julieta Cervantes/Special to the Register)

Though the dramatic weight of the play never leaves Erik’s shoulders — and perhaps is partly responsible for his bad back and sleepless nights — this isn’t a star vehicle with supporting characters, but one in which all are pretty much equal. The interplay of the superb cast, directed by Joe Mantello, sustains an exquisite tension that combines the poetry and farce of everyday living. It seems that each character could be starring in her own play, and none of their lives have turned out as she would have scripted.

Mom is played by Pamela Reed, who deftly navigates between the nurturing and exasperating, the mothering and the smothering. Older daughter Aimee (Therese Plaehn) is a lesbian lawyer who has had a particularly tough year and is doing her best to keep her troubles within. Younger daughter Brigid (Daisy Eagan) is the needy one, hosting at her new apartment, the one she has just moved into with her older boyfriend, Richard (Luis Vega). She wants everything to be perfect. It won’t be. It can’t be.

A scene from "The Humans" at the Seattle Repertory Theatre in Seattle on Nov. 28, 2017.(Photo: Julieta Cervantes/Special to the Register)

It would have been easy to make sibling rivalry a source of tension, or Aimee’s sexuality, but this play doesn’t do “easy.” As the sisters succor and support each other, Richard tries to stay as far from the fray as possible, yet occasionally must engage in conversation with Erik, making it plain that these two versions of the American male live on different planets.

The play shouldn’t be as funny as it is, given the bleakness of its middle-class vision, but the frequent laughter is borne of recognition. And when the play turns even darker, literally and thematically, it is plain where it has been heading all along. Amid all this, there’s “Momo” (Lauren Klein), the grandmother in a wheelchair and the throes of dementia, who somehow emerges as the family’s moral conscience.

Once the Alpha Male, now considerably farther down the alphabet, Erik senses that the rest of them are headed where Momo is. By the end of the play, he is once again all alone. In the dark. Just like the rest of us.